Species: Actinemys marmorata

Western Pond Turtle

Species

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Species of concern in the Puget Sound watershed

Encyclopedia of Puget Sound

Carapace is low and olive, dark brown, or blackish, usually with a pattern of dark radiating spots or lines on each scute; plastron is yellowish, often with dark blotching; top of head has black spots or network; adult males differ from adult females in having the vent posterior to the rear edge of the carapace (vs. at or anterior to the carapace edge), a paler throat, and a shell that usually is flatter and less heavily marked; young are brown or olive above, with yellow on the edge of the marginals and on the head, limbs, and tail; tail of young is nearly as long as the shell; adult carapace length usually 9-19 cm (Stebbins 1985).

Articles:

Western Pond Turtle (Actinemys marmorata, formerly Clemmys marmorata)

August 01, 2013

This article was originally published by the Washington Department of Fish and Wildlife as part of its annual report Threatened and Endangered Wildlife in Washington.

Figure 1. Adult female western pond turtle with an attached radio transmitter and identifying number for population monitoring. Photo by Melissa Reitz.

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Chelonia

Order

Cryptodeira

Family

Emydidae

Genus

Actinemys

NatureServe

Source:
ELEMENT_GLOBAL.2.102191

Classification

Other Global Common Names

Pacific Pond Turtle - tortue de l'Ouest

Informal Taxonomy

Animals, Vertebrates - Turtles

Formal Taxonomy

Animalia - Craniata - Chelonia - Cryptodeira - Emydidae - Actinemys - .

Ecology and Life History

Short General Description

A turtle.

Migration

false - true - false - In a northern California stream, Bury (1972) reported a home range length of 275-2425 meters (average 976 meters for males, 0-750 meters (average 248 meters) for females, and 0-1150 meters (average 363 meters) for juveniles. Some individuals move 2-2.5 kilometers between the lower courses of coastal streams (D. Holland). At two sites in southern California, linear aquatic home ranges of adult females were 658-4263 meters (mean 1273 m)eters and 32-966 meters (mean 335 meters) (Goodman and Stewart 2000).

Non-migrant

false

Locally Migrant

true

Food Comments

This turtle is a scavenger and opportunistic predator with a preference for live prey; adults are partially herbivorous; food items are mostly aquatic (Bury 1986). Diet often includes adult and larval insects, worms, crustaceans, carrion, and algae. Apparently this turtle does not forage on land (Rathbun et al. 2002).

Reproduction Comments

Mating occurs in April-May in central coastal California (see Rathbun et al. 1992). Reproductive females lay one or two clutches of 3-11 eggs, April-August (varies with location); June-August in central coastal California. Incidence of double clutching appears to be very low in the northern part of the range. Egg laying probably peaks in June-July throughout most of the range. In San Bernardino County, California, females that double clutched deposited eggs in May and June (Goodman 1997). Eggs hatch in about 10-12 weeks. Young probably overwinter in nests and emerge in March-April (central coastal California; see Rathbun et al. 1992). Age of first reproduction in females reportedly is about 7-9 years in the south and 10-14 years in the north (Bury 1979, D. Holland), but individuals in some populations exhibit much faster growth (Bury et al. 2010, Germano 2010) and earlier maturation. For example, females in a population in central coastal California reached reproductive maturity as early as 4 years of age (Germano and Rathbun 2008), and females at various sites in southern Oregon took 5-9 years to reach maturity (Germano and Bury 2009). Some live at least 4 decades (R. B. Bury and D. Holland).

Ecology Comments

In a northern California stream, density was estimated at 214 turtles/hectare, based on captures of 578 individuals (35% juveniles) in a 3.5-kilometer stretch of stream (Bury 1972, cited by Ernst et al. 1994). Turtles generally were congregated in separated pools along the stream. Reese and Welsh (1998) stated that Bury (1972) recorded densities as high as 445/hectare. Bury (1979) reported that density of this population was 170 turtles per acre (420/hectare). In California, some populations include 500-1000 individuals per hectare (Holland and Bury manuscript, cited by Reese and Welsh 1998), others only 13-19/hectare (e.g., 1,210 turtles over 63 stream kilometers) (Reese and Welsh 1998). In western Oregon, Nussbaum et al. (1983) stated that one oxbow lake of 1.5-2.0 hectares contained an estimated 75 individuals. Another oxbow lake of about the same size contained an estimated 180 individuals. <br><br>These turtles are subject to predation by various Carnivora and introduced bullfrogs and fishes.

Length

Conservation Status

NatureServe Global Status Rank

G3G4

Global Status Last Reviewed

2006-01-31

Global Status Last Changed

2001-05-21

Distribution

Conservation Status Map

Global Range

G - 200,000-2,500,000 square km (about 80,000-1,000,000 square miles) - G - This turtle is discontinuously distributed and generally uncommon from western Washington (Puget Sound region, at least formerly) south to northwestern Baja California. Isolated populations occur in the Mojave River in California, the Carson River in Nevada (one population in the vicinity of Carson City), the lower Columbia River (two populations in Washington, one in Oregon), the Puget Sound Trough in northern Washington (rarely observed; no known extant populations), and in areas south of the Transverse Ranges in southern California and adjacent Baja California (Bury and Germano 2008). Western pond turtles still exist at probably numerous localities in the Central Valley of California (Germano and Bury 2001). Occurrences in the following locations may represent introductions and may or may not represent extant populations: Truckee, Carson, and Humboldt rivers in western Nevada; southern British Columbia; Snake River, Jerome County, Idaho (1894); and Canyon Creek area, Grant County, Oregon. Elevational range extends from sea level to around 6,000 feet. See Buskirk (1990) for some relatively new records from California, mainly from the Sierra Nevada foothills.

Global Range Code

Global Range Description

200,000-2,500,000 square km (about 80,000-1,000,000 square miles)

ELEMENT_GLOBAL.2.102191